(TNS) — WASHINGTON — Sen. Claire McCaskill of Missouri said Thursday that Russian hackers did not successfully penetrate her Senate office’s computer systems, following a report that one of her policy aides was the target of a phishing attack.

“While this attack was not successful, it is outrageous that they think they can get away with this. I will not be intimidated,” the Democrat said in a statement. “I’ve said it before and I will say it again, (Russian President Vladimir) Putin is a thug and a bully.”

The Daily Beast reported Thursday evening that the e-mail address for McCaskill’s aide was uncovered as part of its investigation into congressional candidates targeted by hacking attempts. A Microsoft official revealed last week that the company had defended three candidates against such attacks.

The hacking attempt reportedly came in the form of a phishing attack, in which the target would receive an e-mail to change his or her password, leading the target to a malicious site that mirrored the legitimate Senate login page. The Daily Beast reported that the tactic was similar to one successfully implemented by Russian hackers when they hacked into the Democratic National Committee in 2016.

McCaskill said last year that she was concerned about cyberattacks targeting her campaign. She is one of the most vulnerable incumbent senators up for re-election this year, running in a state that President Donald Trump carried by 19 points. Inside Elections with Nathan L. Gonzales rates the race a Toss-up.

At the time, she said her campaign was taking steps to address this threat, but she would not disclose those details.

With many educational organizations shifting their entire schedules to distance learning tools or full virtual environments indefinitely, never has the statement “we are all in this together” been more poignant.